The object of the invention is to provide a simple and compact firing mechanism.
According to the invention there is provided a firing mechanism for firing a percussion cap. The mechanism includes a percussion cap support having a position in which the percussion cap is located, a leaf spring fixed at one end thereof to the support and extending across the percussion cap position, a firing pin protruding from one side of the leaf spring towards the percussion cap, a mass disposed on the leaf spring to back up the firing pin, an engagement device engaged under the leaf spring, on the firing pin side of the leaf spring and at the end thereof opposite from the fixed end for preventing access of the firing pin to the percussion cap when in the rest position prior to firing, and means for withdrawing the engagement device to fire the percussion cap, the withdrawal means being manually actuable to move the engagement device, thereby flexing the spring, to a certain position, whereat the engaged end clears the engagement device and there is sufficient energy stored in the spring by flexure that on release of the spring it drives the firing pin into and fires the cap.
In preferred embodiments the spring is lightly stressed against the engagement device when in the rest position, but the energy stored in the spring is insufficient to fire the percussion cap in the event of breakage of the engagement device. In this way accidental firing can be avoided even in the event that the device is dropped or broken.
The engagement device may be a mass, for example a ball or other shape having a cord or handle attached. The mass normally rests beneath the spring and withdrawing it by means of a handle or cord stresses the spring which is then released to fire the percussion cap as the mass is drawn past. The mass may be discarded.
However, in a preferred embodiment of the invention the engagement device is a lever which has a catch portion which engages beneath the the other end of the leaf spring, the lever being manually operable to raise the spring until the catch portion clears it to release the spring and fire the percussion cap.
Preferably, the lever is rigid and is pivoted with respect to the housing. With this arrangement there may be an extension of the lever beyond the fulcrum which can be depressed to urge the lever proper upwardly. However, it is envisaged that there may be no extension beyond the fulcrum and the lever is simply raised manually. The latter arrangement allows a modification in which the lever is flexible or has a flexible portion and is mounted rigidly on the housing as by welding or riveting, flexure of the lever or a hinge portion thereof allowing the required upward movement.
Preferably the lever is aligned with the leaf spring and the fulcrum or fixture point for the lever may then be over the fixture point for the spring or at a place in the housing directly opposite. However, the lever need not be aligned with the leaf spring and the point of fixture or fulcrum can be any desired position.
The catch portion may be a catch depending from the lever to engage beneath the spring. Alternatively, it may be constituted by part of the lever itself which normally rests beneath the end of the spring.
In another preferred embodiment, the firing mechanism further comprises location means for locating the percussion cap support, flexure stress in the spring being reacted via the percussion cap support to the location means during withdrawal of the engagement device to fire the percussion cap.
The invention also provides a rocket and launcher combination comprising a percussion cap, a rocket jet plate having a position wherein the percussion cap is supported, a leaf spring fixed at one end thereof to the rocket jet plate and extending across the percussion cap position, a firing pin protruding from one side of the leaf spring towards the percussion cap; a mass disposed on the leaf spring to back up the firing pin; a rocket body having the rocket jet plate at one end thereof, a rocket launcher at least partially surrounding the rocket body, an engagement device provided in the rocket launcher engaged under the leaf spring, on the firing pin side of the spring and at the end thereof opposite from the fixed end for preventing access of the firing pin to the percussion cap when in the rest position prior to firing, abutment means in the rocket launcher for the rocket jet plate to abut against prior to firing, and means in the rocket launcher for withdrawing the engagement device to fire the percussion cap, the withdrawal means being manually actuable to move the engagement device, thereby flexing the spring, flexure stress in the spring being reacted via the rocket jet plate to the abutment means and the rocket launcher, to a certain position wherein the engaged end clears the engagement device and there is sufficient energy stored in the spring by flexure that on release of the spring it drives the firing pin into and fires the cap.